The technological area of three-dimensional integrated chips (“3D-IC”) and related structures is constantly seeking faster, smaller, and more powerful structures for use in computers and computer devices. This can result in chip structures that are increasingly more densely packed and have ever greater levels of power consumption. Further, chip structures can include many chips in single packages and/or stacks arrangements of multiple
packages. In one example, central processing units or general processing units can include a control chip included in a package with an additional package or packages stacked thereon that include memory chips, such as DRAM or the like. Such structures can be used as processors for smartphones or the like where a small footprint or overall size for the assembly is sought.
In these and other assemblies including stacked arrangements of integrated circuit chips and the like, and in particular those with high circuit density or high power consumption, heat dissipation can negatively impact chip performance. For example, in vertically stacked arrangements, heat tends to dissipate vertically through the structure, meaning that heat from, for example, a control or logic chip can end up dissipating into memory chips stacked thereon as the heat is conducted through the stack. This phenomenon can cause overall heating of chips in a stack to undesirable levels, either throughout the entire chip or in various “hot spots” in which a spatial temperature gradient is created in a chip by heat dissipation from lower chips. In either form, such heat can cause decreased chip performance or partial or complete chip failure. Accordingly, heat dissipation is important for such structures.
Heat dissipation has been dealt with in stacked chip arrangements, for example, by attempts to make vertical heat dissipation as fast as possible, such as by including large heat spreader structures that can include a plurality of fins or the like, on top of a stacked chip arrangement. However, this undesirably increases the size of the assembly. Additionally, active cooling systems have been introduced to dissipate heat more quickly and in some instances in lateral directions, rather than vertical. However, for many applications, such as mobile devices or the like, the increase in overall power consumption required by active cooling is undesirable. Accordingly, further advances are needed.